Petco Text Logo
Petco Pet Logo

My fish has fin rot and a white filament. What's the right treatment?

Updated On September 23rd, 2025

Pet's info: Fish | Unknown - Fish | Male

So since the last time I asked he started to show signs of fin rot and this morning I saw one thin white filament attached to his left fin. Doesn't appear to be attached to his body anywhere else but his one fin. He is in a 1 gal tank and I put a fungal treatment in his bowl. Was this the right way to go or should I simply keep with salt and pristine water

1 Answer

Most Helpful Answer

Image profile

Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on September 21st, 2018

Maintain pristine water quality regardless of any other treatment. Clean water is the foundation for treatment and recovery. You can use aquarium salt, but no more for 14 days. An anti fungal medication may work *if* the condition is fungal. If it is bacterial, it won't help. You can try an 'all in one' product, such as Lifeguard (by Tetra). Find it in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated.

Vote icon

1Pet Parents found this answer helpful

image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Sponsored